The present invention relates to devices for securing sliding windows and the like in a fully closed or partially opened, vented position.
A sliding window generally has a primary locking mechanism to maintain the window in a closed position and to restrain it from being moved along a channel portion of the frame towards an open position. However, these locks may be quite easy to force open and is usually operable only when the window is in the closed position.
For these reasons, secondary locking devices exist which are employed to physically impede movement of the window within the channel. These secondary locks are easy to install and are typically removed from the access of a would-be intruder. In addition, many of these locks may be positioned to allow a selected amount of movement of the window towards the open position for venting, but to deny a would-be intruder sufficient access that could otherwise be gained by more fully opening the window.
One prior art secondary lock that has been proven somewhat effective is a clamp that attaches to a selected location within the channel and physically impedes the movement of the window. These clamps, however, must be attached with sufficient tenacity to avoid being forced loose by a would-be intruder. The required tenacity detracts from ready re-installation of the secondary lock to allow the window an adjustable range of movement or venting. In addition, installation of the aforementioned clamps may cause unsightly gouging to the window channel which is revealed if a clamp is re-installed at a different location in the channel. For these reasons, such locks typically are installed once only, either at a position immediately at the window's trailing edge so as to serve the function of a backup locking mechanism, or at a distance removed from the trailing edge of the window along the channel so as to allow the window a limited range of movement towards the open position for venting.
Another simple and common type of device for locking sliding windows comprises a relatively long and narrow bar of metal, wood or plastic loosely disposed in the bottom channel of the sliding window frame, between the sliding window and a vertical frame member, or abutment, so as to block the sliding movement of the window. The length of the bar is usually selected either to secure the window in a fully locked position, or to permit venting by allowing the window to be opened slightly before it encounters and is stopped by the bar. Some devices of this type have extensions which allow them to secure a window in either a fully closed or partially open, vented position.
The simplest such bar locks are comprised as elongated bars that are wedged between the trailing edge of the window and an abutment, or are otherwise positioned within the window's channel so as to allow the window a limited range of movement toward the open position. The more complicated bar locks, as mentioned, are telescopic or otherwise permit variations in their length to allow the occupant to select between desired degrees of venting or retention of the window in the closed position.
Devices of the types described above frequently possess certain drawbacks. For example, these devices are designed to stop the window by a bracing force applied against the bottom of the window. As a result, the window can sometimes be jarred and lifted over the device. Moreover, in the case of bar locks, the locking devices are not normally attached to either the window or the frame, and can sometimes be easily dislodged from the bottom channel of the window frame in which they rest, particularly when the window is opened for venting purposes. Also, the bar locks may need to be specifically tailored to a particular window, since the width of the bar relative to the window channel may facilitate dislodgement, or prevent usage with a relatively narrower window channel. While they may permit some length variation in the range of movement permitted to the window, alterations to the length of the bar are typically not easily accomplished, or are easily accomplished only at the expense of sturdiness or resistance to dislodgement.
The security problems that arise with respect to sliding doors or windows are particularly acute when venting is desired. Although the vent opening is typically too narrow for even a small child to pass through, it is usually sufficiently wide for someone to introduce a pole or other elongated implement for the purpose of dislodging the bar from either the bottom of the sliding window channel or from the cradle supporting the free end of the bar. Therefore, a significant disadvantage of existing bar-type devices for securing sliding windows and the like is that they are either fairly easily overridden and dislodged, or they are too elaborate, costly, and inconvenient to use.
From the foregoing, it should be apparent that a need exists for a simple, inexpensive device which is easy to install and use, for securing sliding windows and the like, and which will not be easily dislodged from the sliding window channel. This device should be rigidly retained in place whether the sliding window is fully locked or partially opened for venting purposes, and should be readily adaptable to lock a wide range of sliding windows. The present invention satisfies these needs and provides further related advantages.